Wiring power up a Jetta.

I'm planning on wiring up a 150W opus PSU somehow. I'm thinking I can run 12 gauge wire to the distribution block on the battery, through the grommet in the firewall, along the door trim on the drivers side, then to the trunk through the seats. I should also try to run a inline fuse rated at 30 or so amps near the distribution block.

Im not sure about the jetta, but for the passat (should be the same) there are two entry points into the cabin. One is through the ECU box on the drivers side which is kind of tricky to do because the ECU box is water tight so you have to drill a hole in the box and make sure its sealed when your done, or drill a hole through the firewall. THe second is on the passenger side, inside the glove box. Remove the glove box and you'll see the hole. There may also be another entry point on the drivers side, following the door, up through the fuse box and up or under some relays.

Thanks for the suggestion of going to 8AWG. Does the amperage on the fuse sound good too? Also what gauge of wire should I use for the ignition? I hear I can go into the back of the fusebox and use the window wiper circuit since it operates only when the ignition is on.

I found that there are a couple grommets that go through the firewall near the power steering on a MkIV.